Flexible display device and method of controlling same

ABSTRACT

A flexible display device is provided. The flexible display device includes: a display; a sensor configured to detect at least one rolling characteristic in response to the display being rolled; and a controller configured to perform a first function of the flexible display device based on the detected at least one rolling characteristic.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 16/298,104, filed on Mar. 11, 2019, which is a ContinuationApplication of U.S. application Ser. No. 14/419,130, filed on Feb. 2,2015, was issued U.S. Pat. No. 10,241,542 on Mar. 26, 2019, which is aNational Phase Application of International Patent Application No.PCT/KR2013/006951, filed Aug. 1, 2013, claiming priority from KoreanPatent Application No. 10-2012-0084512, filed Aug. 1, 2012. Thedisclosures of the prior applications are hereby incorporated in theirentireties by reference.

BACKGROUND 1. Field

The present general inventive concept relates to a flexible displaydevice and a method of controlling the same, and more particularly, to aflexible display device including a flexible display unit and a methodof controlling the same.

2. Description of the Related Art

Recent developments in electronic technologies have brought about thedevelopment of various types of display devices. In particular, displaydevices, such as a TV, a PC, a laptop computer, a tablet PC, a portablephone, an MP3 player, etc., have been widely distributed to be used inmost households.

In order to meet the needs of users who want newer and more of a varietyof functions, efforts to develop newer forms of display devices havebeen made. These types of display devices are named next generationdisplays.

A flexible display device is an example of next generation displaydevices. The flexible display device refers to a display device having adeformable characteristic like paper.

Since a user applies a force to the flexible display device to bend theflexible display device and change a shape thereof, the flexible displaydevice may be variously used. For example, the flexible display devicemay be realized as a portable device such as a portable phone, a tabletPC, an electronic frame, a personal digital assistant (PDA), an MP3player, etc.

The flexible display device has a flexible characteristic unlikeexisting display devices. Therefore, there is a need for methods ofdisplaying a screen appropriate for a flexible display device having achanged shape.

SUMMARY

The exemplary embodiments provide a flexible display device forperforming various functions when rolling and/or bending the flexibledisplay device, and a method of controlling the same.

According to an aspect of the exemplary embodiments, there is provided aflexible display device including: a display; a sensor configured todetect at least one rolling characteristic in response to the displayunit being rolled; and a controller configured to perform a firstfunction of the flexible display device based on the detected at leastone rolling characteristic.

The display unit may be rolled based on one axis.

The rolling characteristic may include at least one from among a rollingdiameter and a rolling area of the display unit.

In response to the display being rolled and the rolling diameter beingchanged, the controller may perform a second function corresponding tothe changed rolling diameter.

Upon a condition that the display includes a plurality of rolling areas,the sensor may detect rolling diameters respectively corresponding tothe plurality of rolling areas. Upon a condition that the display unitis rolled and at least one from among the rolling diameters respectivelycorresponding to the plurality of rolling areas is changed, thecontroller may perform a third function corresponding to the changed atleast one from among the rolling diameters.

The controller is configured to perform a second function in response torolling an entire area of the display and a third function in responseto partial partially rolling a partial area of the display.

The second function may be a screen mode change function, and the thirdfunction may be a sub-function of content already being displayed on thedisplay unit.

In response to at least a partial area of the display being exposedbased on a manipulation of unrolling the display unit, the controllermay reconstitute an image according to a size of the exposed partialarea to display the reconstituted image in the exposed partial area.

According to an aspect of the exemplary embodiments, there is provided amethod of controlling a flexible display device, the method including:detecting at least one rolling characteristic in response to a displayof the flexible display device being rolled; and performing a firstfunction of the flexible display device based on the detected at leastone rolling characteristic.

The display may be rolled based on one axis.

The rolling characteristic may include at least one from among a rollingdiameter and a rolling area of the display.

The method may further include: upon a condition that the display unitis rolled and the rolling diameter is changed, performing a secondfunction corresponding to the changed rolling diameter.

The method may further include: upon a condition that the displaycomprises a plurality of rolling areas, detecting rolling diametersrespectively corresponding to the plurality of rolling areas; and upon acondition that the display is rolled and at least one from among therolling diameters respectively corresponding to at least one from amongthe plurality of rolling areas is changed, performing a second functioncorresponding to the changed at least one from among the plurality ofrolling diameters.

The method may further include: performing a second function in responseto rolling an entire area of the display and performing a third functionin response to partially rolling a partial area of the display.

The second function may be a screen mode change function, and the thirdfunction may be sub-function of a content already being displayed on thedisplay.

The method may further include: in response to at least a partial areaof the display being exposed according to a manipulation of unrollingthe display unit, reconstituting an image according to a size of theexposed partial area to display the reconstituted image in the exposedpartial area.

The flexible display device may further comprise a main body, whereinthe display is operable to be pulled out of the main body.

The display of the flexible display device may comprise at least onefrom among bend sensors, strain gauges, and acceleration sensors todetermine a degree of rolling in which the display has been rolled.

If the display is partially rolled, a portion of the display that is notrolled comprises a display surface of an image or moving image.

According to an exemplary embodiment, there is provided a flexibledisplay device comprising: a display; a sensor configured to detect oneof a twisting characteristic, a bending characteristic, and a foldingcharacteristic when the display is one of twisted, bent, and folded; anda controller configured to perform a first function of the flexibledisplay device based on the detected one of the twisting characteristic,the bending characteristic, and the folding characteristic.

If the display is partially twisted, partially bent, or partiallyfolded, a portion of the display that is not twisted, bent, or foldedcomprises a display surface of an image or moving image.

According to yet another exemplary embodiment, there is provided asystem comprising a flexible display device and a support unit. Theflexible display device comprises: a display; a sensor configured todetect at least one rolling characteristic in response to the displaybeing rolled; and a controller configured to perform a first function ofthe flexible display device based on the detected at least one rollingcharacteristic, wherein the first function is performed when the displayis rolled and inserted into the support unit.

The first function as mentioned above includes displaying an image on aportion of the rolled display that is not covered by the support unit.

According to various exemplary embodiments as described above, aflexible display device may be used in various ways, and thusconvenience of users may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a structure of a flexible displaydevice according to an exemplary embodiment.

FIG. 2 is a view illustrating a basic structure of a display unit of aflexible display device, according to an exemplary embodiment.

FIGS. 3A and 3B are views illustrating a shape of a flexible displaydevice, according to an exemplary embodiment.

FIG. 4 is a view illustrating a shape of a flexible display device,according to another exemplary embodiment.

FIGS. 5A, 5B, 5C and 5D are views illustrating a method of rolling aflexible display device, according to an exemplary embodiment.

FIGS. 6A, 6B, 6C, 6D, 7A, 7B, 8A, 8B, 8C and 8D are views illustratingchanges in a shape of a flexible display device, according to anexemplary embodiment.

FIGS. 9A, 9B, 9C and 9D are views illustrating a method of sensing abending direction by using bend sensors that overlap each other,according to an exemplary embodiment.

FIGS. 10A and 10B are views illustrating a method of sensing a bendingdirection, according to another exemplary embodiment.

FIG. 11 is a block diagram illustrating a detailed structure of aflexible display device to describe operations according to variousexemplary embodiments.

FIG. 12 is a block diagram illustrating a detailed structure of acontrol unit of FIG. 11.

FIG. 13 is a block diagram illustrating a software structure of astorage unit for supporting an operation of the control unit of FIG. 11.

FIGS. 14A and 14B are views illustrating a rolling characteristicaccording to an exemplary embodiment.

FIGS. 15A, 15B and 15C are views illustrating a rolling characteristic,according to another exemplary embodiment.

FIGS. 16A, 16B and 16C are views illustrating a method of controlling aflexible display device, according to an exemplary embodiment.

FIGS. 17A and 17B are views illustrating a method of controlling aflexible display device, according to another exemplary embodiment.

FIGS. 18A, 18B, 19A, 19B, 19C, 19D, 20A and 20B are views illustrating amethod of controlling a flexible display device, according to anotherexemplary embodiment.

FIGS. 21A, 21B, 22A, 22B, 22C, 22D, 23A, 23B, 24A, 24B, 24C, 24D, 24E,25, 26, 27A, 27B, 27C, 28A, 28B, 28C and 29 are views illustrating amethod of controlling a flexible display device, according to anotherexemplary embodiment.

FIGS. 30 and 31 are views illustrating flexible display devices,according to various exemplary embodiments.

FIG. 32 is a flowchart illustrating a method of controlling a flexibledisplay device, according to an exemplary embodiment.

DETAILED DESCRIPTIONS OF THE EXEMPLARY EMBODIMENTS

Hereinafter, the exemplary embodiments will be described in detail withreference to the attached drawings.

FIG. 1 is a block diagram illustrating a structure of a flexible displaydevice according to an exemplary embodiment. Referring to FIG. 1, aflexible display device 100 includes a display unit 110, a sensing unit120, and a control unit 130.

The flexible display device 100 of FIG. 1 may be realized as varioustypes of devices having portability and display functions, like aportable phone, a portable media player (PMP), a PDA, a tablet PC, anavigation system, etc. The flexible display device 100 may be realizedas a portable device and a stationary device such as a monitor, a TV, akiosk PC, or the like.

The display unit 110 displays a screen. Here, the screen may include aplay screen or an execution screen for contents such as images, movingpictures, texts, etc., various types of UI screens, etc.

The flexible display device 100 including the display unit 110 has abendable characteristic. Therefore, the display unit 110 may be formedof a bendable material in a bendable structure. A detailed structure ofthe display unit 110 will now be described with reference to FIG. 2.

FIG. 2 is a view illustrating a basic structure of a display unit of aflexible display device according to an exemplary embodiment. Referringto FIG. 2, the display unit 110 includes a substrate 111, a driver 112,a display panel 113, and a protecting layer 114.

The flexible display device 100 refers to a device that keeps a displaycharacteristic of an existing flat-panel display device but may betwisted, bent, folded, or rolled. Therefore, the flexible display device100 may be manufactured on a flexible substrate.

In detail, the substrate 111 may be realized as a plastic substrate (forexample, a polymer film) that may be deformed by external pressure.

The plastic substrate has a structure in which barrier coating isperformed on both sides of a base film. The base film may be realized asvarious types of resins such as Polyimide (PI), Polycarbonate (PC),Polyethyleneterephtalate (PET), Polyethersulfone (PES),Polythylenenaphthalate (PEN), Fiber Reinforced Plastic (FRP), etc. Also,the barrier coating may be performed on facing sides of the base filmand may be formed of an organic or inorganic layer to keep flexibility.

The substrate 111 may be formed of a material having a flexiblecharacteristic such as thin glass, metal foil, or the like, instead ofor in addition to the plastic substrate.

The driver 112 drives the display panel 113. In detail, the driver 112applies a driving voltage to a plurality of pixels constituting thedisplay panel 113 and may be realized as an a-si TFT, a low temperaturepoly silicon (LTPS) TFT, an organic TFT, or the like. The driver 112 maybe realized as various types of the display panel 113. For example, thedisplay panel 113 may include an organic emitter including a pluralityof pixel cells and an electrode layer covering both sides of the organicemitter. In this case, the driver 112 may include a plurality oftransistors respectively corresponding to the pixel cells of the displaypanel 113. The control unit 130 applies an electric signal to gates ofthe respective transistors so as to enable the pixel cells connected tothe transistors to emit light. Therefore, an image may be displayed.

Alternatively, the display panel 113 may be realized as an organiclight-emitting diode, an electroluminescent light (EL), anelectrophoretic display (EPD), an electrichromic display (ECD), a liquidcrystal display (LCD), an active-matrix liquid-crystal display (AMLCD),a plasma display panel (PDP), or the like. However, the LCD may notself-emit light and thus needs additional backlight. The LCD that doesnot use backlight uses ambient light. Therefore, in order to use the LCDdisplay panel 113 without backlight, an outdoor environment having alarge amount of light may be satisfactory as an environment for usingthe LCD display panel 113 without backlight.

The protecting layer 114 protects the display panel 113. For example,the protecting layer 114 may be formed of a material such as ZrO, CeO2,ThO2, or the like. The protecting layer 114 may be formed of atransparent film to cover a whole surface of the display panel 113.

Differently from what is shown in FIG. 2, the display unit 110 may berealized as electronic paper. The electronic paper refers to a displaywhere a characteristic of normal ink is applied to paper and which usesreflected light and thus is different from a general flat-panel display.The electronic paper may change pictures or characters by usingelectrophoresis using a twisted ball or capsule.

If the display unit 110 is an element formed of a transparent material,the display unit 110 may be realized as a display device having bendableand transparent characteristics. For example, if the substrate 111 isformed of a polymer material such as plastic having a transparentcharacteristic, the driver 112 is realized as a transparent transistor,and the display panel 113 includes a transparent organic light-emittinglayer and a transparent electrode, the display unit 110 may havetransparency.

The transparent transistor refers to a transistor that is manufacturedby replacing opaque silicon of an existing thin film transistor with atransparent material such as transparent zinc oxide, titanium oxide, orthe like. Also, the transparent electrode may be formed of a newmaterial such as indium tin oxide (ITO) or graphene. The graphene refersto a material where carbon atoms are connected to one another to form ahoneycombed planar structure and which has a transparent property. Thetransparent organic light-emitting layer may also be formed of variouskinds of materials.

FIGS. 3A and 3B are views illustrating a shape of a flexible displaydevice according to an exemplary embodiment.

Referring to FIG. 3A, the flexible display device 100 includes a mainbody 2100, a display unit 110, and a gripper 2200.

The flexible display device 100 refers to a device that keeps a displaycharacteristic of an existing flat-panel display device but may betwisted, bent, folded, or rolled like paper. Therefore, the flexibledisplay device 100 including the display unit 110 may have a bendablecharacteristic, and the display unit 110 may be formed of a bendablematerial in a bendable structure. This will be described later withreference to FIGS. 5A through 5D.

The main body 2100 operates as a kind of case housing the display unit110. The main body 2100 includes a rotating roller that rolls thedisplay unit 110. Therefore, when the display unit 110 is not used, thedisplay unit 110 may be rolled on the rotating roller to be housed inthe main body 2100.

If a user grips the gripper 2200 to pull the display unit 110, therotating roller rotates in an opposite direction to the rollingdescribed above, to unroll the display unit 110, and thus the displayunit 110 comes out of the main body 2100. The rotating roller mayinclude a stopper (not shown). Therefore, if the user pulls the gripper2200 to a preset distance or more, rolling of the rotating roller may bestopped by the stopper, and the display unit 110 may be fixed.

If the user presses a button of the main body 2100 to stop the stopper,the stopper stops the display unit 110 from being rotating in or out ofthe stopper. Subsequently, the rotating roller may rotate in a backwarddirection, and thus the display unit 110 may be rolled into the mainbody 2100. The stopper may have a switch shape that stops an operationof a gear for rotating the rotating roller that affects movement of thedisplay unit in and out of the stopper. An existing rolling structuremay be applied to structures of the rotating roller and the stopper asit is, and thus their detailed illustrations and descriptions will beomitted.

The main body 2100 includes a power unit (not shown). The power unit maybe realized as various types such as a battery connector in which adisposable battery is installed, a secondary battery which may becharged and used a plurality of times by the user, a solar battery whichproduces electric power by using solar heat, etc. If the power unit isrealized as the secondary battery, the user may connect the main body2100 to an external power source to charge the power unit (not shown).

The main body 2100 having a cylindrical structure is illustrated inFIGS. 3A and 3B but may be realized in a rectangular shape, a polygonalshape, or the like.

FIG. 4 is a view illustrating a shape of a flexible display deviceaccording to another exemplary embodiment. Referring to FIG. 4, a powerunit 2300 is installed at an edge of a side of the flexible displaydevice 100 to be attached to and detached from the flexible displaydevice 100.

The power unit 2300 may be formed of a flexible material to be benttogether with the display unit 110. In detail, the power unit 2300 mayinclude a cathode current collector, a cathode, an electrolyte part, ananode, an anode current collector, and a coating covering the cathodecurrent collector, the cathode, the electrolyte, the anode, and theanode current collector.

For example, the cathode current collector may be formed of: an alloymaterial such as a TiNi-based material having a high elasticcharacteristic; a pure metal material such as copper, aluminum, or thelike; pure metal coated with carbon; a conductive material such ascarbon, carbon fiber, or the like; and/or a conductive polymer such aspolypyrrole, or the like.

The cathode may be formed of a cathode material such as a metal materialsuch as lithium, sodium, zinc, cadmium, a hydrogen storage alloy, lead,or the like, a nonmetal material such as carbon or the like, and apolymer electrode material such as organic sulfur.

The anode may be formed of an anode material such as sulfur, metalsulfide, LiCoO2, lithium transition metal oxide, SOCl2, MnO2, Ag2O, Cl2,NiCl2, NiOOH, a polymer electrode, or the like. The electrolyte part maybe realized as a gel type using PEO, PVdF, PMMA, PVAC, or the like.

The coating may be formed of a normal polymer resin. For example, PVC,HDPE, epoxy resin, or the like may be used. Any material that mayprevent damage to a thread-shaped battery and may be freely twisted orbent may be used as the coating.

The anode and the cathode of the power unit 2300 may respectivelyinclude connectors to be electrically connected to the outside.

Referring to FIG. 4, the connectors protrude from the power unit 2300,and grooves corresponding to positions, sizes, and shapes of theconnectors are formed in the display unit 110. Therefore, the connectorsmay be combined with the grooves to combine the power unit 2300 with thedisplay unit 110. The connectors of the power unit 2300 may be connectedto a power connecting pad (not shown) of the flexible display device 100to supply power to the flexible display device 100. A supporting part2400 is installed at an edge of another side of the flexible displaydevice 100. In detail, the supporting part 2400 may be formed of aflexible material to be bent together with the display unit 110 and mayoperate as an axis on which the display unit 110 is rolled. The displayunit 110 may be rolled by using the power unit 2300 as an axis.

The power unit 2300 is attached to and detached from the edge of theside of the flexible display device 100 in FIG. 4, but this is only anexemplary embodiment. Therefore, a position and a shape of the powerunit 2300 may variously vary according to a product characteristic (or acharacteristic of the flexible display device 100). For example, if theflexible display device 100 is a product having a preset thickness, thepower unit 2300 may be installed on a back side of the flexible displaydevice 100. In this case, additional supporting parts (not shown) may beinstalled on both sides of the flexible display device 100 to operate asaxes on which the display unit 110 is rolled.

FIGS. 5A through 5D are views illustrating a method of rolling aflexible display device according to an exemplary embodiment.

In an exemplary embodiment, the flexible display device 100 includes thedisplay unit 110, and thus rolling of the flexible display device 100may mean that the display unit 110 is rolled.

FIGS. 5A and 5B illustrate a method of rolling the display unit 110 inthe flexible display device 100 including the main body 2100 having thecylindrical structure. In detail, as shown in FIG. 5A, the display unit110 that comes out of the main body 2100 may be rolled by using the mainbody 2100 as an axis. Also, as shown in FIG. 5B, the display unit 110that comes out of the main body 2100 may be rolled by using the gripper2200 as an axis.

FIGS. 5C and 5D illustrate a method of rolling the display unit 110 inthe flexible display device 100 including the power unit 2300 that isinstalled at an edge area of a side thereof. In detail, as shown in FIG.5C, the display unit 110 may be rolled by using the supporting part 2400as an axis. Also, as shown in FIG. 5D, the display unit 110 may berolled by using the power unit 2300 as an axis.

As described above, the display unit 110 may be rolled according tovarious methods. However, these are only exemplary embodiments, and thusthe display unit 110 may be rolled without an additional axis accordingto a characteristic of the display unit 110. Therefore, the shapes ofthe flexible display device 100 shown in FIGS. 3A through 4 are onlyexemplary embodiments, and thus the flexible display device 100 may berealized in various shapes. A constant force may be continuously appliedto the display unit 110 to keep the display unit 110 rolled. Also, thedisplay unit 110 may be kept rolled until an additional force is appliedto make the display unit 110 flat.

As described above, the flexible display device 100 may be bent byexternal pressure so as to change a shape thereof. The shape-changingmay include bending and rolling of the flexible display device 100.

“Bending” means that the flexible display device 100 is bent.

“Rolling” means that the flexible display device 100 is rolled. Forexample, rolling may be defined as bending the display unit 110 at apreset bending angle or more that is sensed in a preset area. Also, therolling may be defined such that a rolled cross-section of the flexibledisplay device 100 has a shape that is substantially close to a circleor an ellipse.

However, the definitions of the various changed shapes as describedabove are only exemplary embodiments, and thus the various changedshapes may be differently defined according to a type, a size, a weight,a characteristic, etc. of the flexible display device 100. For example,if the flexible display device 100 is bendable to enable surfaces of theflexible display device 100 to meet each other, the rolling may bedefined that front and back surfaces of the flexible display device 100touch each other due to the bending.

FIGS. 6A through 8D are views illustrating a method of sensing a changein a shape of a flexible display device, i.e., bending and rolling ofthe flexible display device, according to an exemplary embodiment.

The sensing unit 120 senses a change in a shape of the flexible displaydevice 100. Here, the change in the shape may include bending or rollingof the display unit 110.

In particular, if the display unit 110 is rolled, the sensing unit 120detects a rolling characteristic. Here, the display unit 110 may berolled on an axis, and the axis, i.e., a rolling axis, may be a linethat connects centers of circles formed by a display surface due torolling. Also, the rolling characteristic may be at least one selectedfrom a rolling diameter, and a size, a position, and a shape of anexposed area. In this case, the rolling diameter may be an average valueof diameters of innermost and outermost surfaces of the display unit 110that is rolled or the diameter of the outermost surface. If the displayunit 110 is partially rolled, the rolling diameter may be a diameter ofa partially rolled area of the display unit 110. Also, if a plurality ofrolling areas (e.g., areas that have been rolled) exist in the displayunit 110, the sensing unit 120 may detect rolling characteristicsrespectively corresponding to the plurality of rolling areas.

For this, the sensing unit 120 may include bend sensors that arearranged on one surface such as a front or back surface of the displayunit 110 or bend sensors that are arranged on the front and backsurfaces.

Here, the bend sensors refer to sensors that are bendable and haveresistance values varying with a bending degree. The bend sensors may berealized as various types such as optical fiber bending sensors,pressure sensors, strain gauges, etc.

FIGS. 6A through 6D are views illustrating an arrangement shape of bendsensors according to an exemplary embodiment.

FIG. 6A illustrates a plurality of bar-shaped bend sensors that arearranged in horizontal and vertical directions in the display unit 110to form a lattice shape. In detail, the bend sensors include bendsensors 11-1 through 11-5 that are arranged in a first direction andbend sensors 12-1 through 12-5 that are arranged in a second directionperpendicular to the first direction. The bend sensors may be arrangedsuch that there are preset distances between one another.

Five bend sensors 11-1 through 11-5 and five bend sensors 12-1 through12-5 are respectively arranged in the horizontal and vertical directionsin FIG. 6A, but this is only an exemplary embodiment. The numbers ofbend sensors may be changed according to a size of the display unit 110,etc. The bend sensors are arranged in the horizontal and verticaldirection as described above to sense bending of all areas of thedisplay unit 110. Therefore, if only parts of a device have flexiblecharacteristics or bending of only parts of the device may be sensed,bend sensors may be arranged at corresponding parts.

The bend sensors may be installed on a front surface of the display unit110 as shown in FIG. 6A, but this is only an exemplary embodiment.Therefore, the bend sensors may be installed on a back surface of thedisplay unit 110 or on both the front and back surfaces of the displayunit 110.

Also, shapes, numbers, and arrangement positions of the bend sensors maybe variously changed. For example, one bend sensor or a plurality ofbend sensors may be combined with the display unit 110. Here, the onebend sensor may sense one piece of bending data or may have a pluralityof sensing channels that sense a plurality of pieces of bending data.

FIG. 6B illustrates one bend sensor that is arranged on a surface of thedisplay unit 110, according to an exemplary embodiment. As shown in FIG.6B, a bend sensor 21 may be arranged in a circle shape on a frontsurface of the display unit 110. However, this is only an exemplaryembodiment, and thus the bend sensor 21 may be arranged on a backsurface of the display unit 110 and may be realized in a closed curveshape forming various polygons such as a rectangular shape, etc.

FIG. 6C illustrates two bend sensors that are arranged to cross eachother, according to an exemplary embodiment. Referring to FIG. 6C, afirst bend sensor 71 is arranged in a first diagonal direction on afirst surface of the display unit 110, and a second bend sensor 22 isarranged in a second diagonal direction on a second surface.

According to the above-described various exemplary embodiments,line-shaped bend sensors are used. However, a plurality of strain gaugesmay be used to sense bending.

FIG. 6D illustrates a plurality of strain gauges that are arranged onthe display unit 110. The strain gauges sense changes in a shape of asurface of an object to be measured, according to changes in aresistance value of metal or semiconductor having resistance greatlyvarying according to a strength of an applied force. In general, if alength of a material such as metal increases according to an externalforce, a resistance value of the material increases. If the length ofthe material decreases, the resistance value decreases. Therefore, if achange in a resistance value is sensed, a change in a shape of theflexible display device 100 may be sensed.

Referring to FIG. 6D, a plurality of strain gauges are arranged in anedge area of the display unit 110. The number of strain gauges may varyaccording to a size, a shape, preset bending sensing, a resolution, etc.of the display unit 110.

Hereinafter, a method of sensing a change in a shape of the flexibledisplay device 100 by using bend sensors or strain gauges arranged in alattice shape will be described.

The bend sensors may be realized as electric resistance type sensorsusing an electric resistance or micro optical fibers using a strain rateof an optical fiber. Hereinafter, for convenience of description, thebend sensors will be described as being realized as electric resistancetype sensors.

FIGS. 7A and 7B are views illustrating a method of sensing bending in aflexible display device, according to an exemplary embodiment.

If the display unit 110 is bent, bend sensors that are arranged on asurface or both surfaces of the display unit 110 are bent together andoutput resistance values corresponding to an intensity of an appliedtensile force.

In other words, the sensing unit 120 may sense resistance values of thebend sensors by using an intensity of a voltage applied to the bendsensors or an intensity of a current flowing in the bend sensor and maysense bending states in positions of the corresponding bend sensorsaccording to sizes of the resistance values.

For example, as shown in FIG. 7A, if the display unit 110 is bent in ahorizontal direction, bend sensors 41-1 through 41-5 that are installedon a front surface of the display unit 110 are also bent and outputresistance values according to an intensity of the applied tensileforce.

In this case, the intensity of the applied tensile force increases inproportion to a bending degree. For example, if bending is performed asshown in FIG. 7A, a bending degree of a central area is the greatest.Therefore, the greatest tensile force acts on point a3 of the bendsensor 41-1, point b3 of the bend sensor 41-2, point c3 of the bendingsensor 41-3, point d3 of the bend sensor 41-4, and point e3 of the bendsensor 41-5 belonging to the central area. Therefore, the points a3, b3,c3, d3, and e3 have the greatest resistance values.

The bending degree becomes weaker toward the outside. Therefore, thebend sensor 41-1 has a resistance value that is smaller to the right andleft directions of a3 and point a1 has a resistance value that issmaller than at the point a3. Further, point a1, which is not bent, anarea to the left of the point a1, point a5, and an area to the right ofthe point a5 have resistance values that are the same as before bendingis performed. This is equally applied to the other bend sensors 41-2through 41-5.

The sensing unit 120 may sense positions, sizes, and the number ofbending areas, sizes, positions, the number, and directions of thebending lines, the number of times being bent, etc., based on relationsbetween points at which changes in resistance values of the bend sensorsare sensed.

The bending areas refer to areas of the display unit 110 that are bent.Since the bend sensors are bent together, the bending areas may bedefined as all points at which bend sensors outputting resistance valuesdifferent than in a circle state are arranged. Areas in which resistancevalues are not changed may be defined as flat areas that are not bent.

If distances between points at which changes in resistance values aresensed are within preset distances, the sensing unit 120 senses pointsoutputting resistance values as one bending area. If the distancesbetween the points at which the changes in the resistance values aresensed exceed the preset distances, the sensing unit 120 may classifythe points as different bending areas.

As described above, in FIG. 7A, points a1 through a5 of the bend sensor41-1, points b1 through b5 of the bend sensor 41-2, points c1 through c5of the bend sensor 41-3, points d1 through d5 of the bend sensor 41-4,and points e1 through e5 of the bend sensor 41-5 have resistance valuesdifferent than in the circle state.

In this case, points of the bend sensors 41-1 through 41-5 at whichchanges in resistance values are sensed are positioned within presetdistances to be sequentially arranged.

Therefore, the sensing unit 120 senses an area 42, including the pointsa1 through a5 of the bend sensor 41-1, the points b1 through b5 of thebend sensor 41-2, the points c1 through c5 of the bend sensor 41-3, thepoints d1 through d5 of the bend sensor 41-4, and the points e1 throughe5 of the bend sensor 41-5, as one bending area.

The bending area may include a bending line. The bending line may bedefined as a line that connects points of each bending area from whichthe greatest resistance values are detected.

For example, as shown in FIG. 7A, a line 43, which connects the point a3outputting the greatest resistance value in the bending sensor 41-1, thepoint b3 outputting the greatest resistance value in the bend sensor41-2, the point c3 outputting the greatest resistance value in the bendsensor 41-3, the point d3 outputting the greatest resistance value inthe bend sensor 41-4, and the point e3 outputting the greatestresistance value in the bend sensor 41-5, may be defined as a bendingline. FIG. 7A illustrates a bending line that is formed in a verticaldirection in a central area of a display surface.

FIG. 7A describes that the display unit 110 is bent in a horizontaldirection and thus illustrates only bend sensors that are arranged inthe horizontal direction among bend sensors arranged in a lattice shape.In other words, bend sensors arranged in the vertical direction maysense that the display unit 110 is bent in the vertical direction, byusing the same method as when the display unit 110 is bent in thehorizontal direction. Also, if a shape of the display unit 110 ischanged in a diagonal direction, a tensile force is applied to all ofbend sensors arranged in the horizontal and vertical directions.Therefore, the change in the shape of the display unit 110 in thediagonal direction may be sensed based on output values of the bendsensors arranged in the horizontal and vertical directions.

The sensing unit 120 may sense bending of the display unit 110 by usingstrain gauges.

In detail, if the display unit 110 is bent, a force acts on straingauges arranged in an edge area of the display unit 110, and the straingauges output different resistance values according to an intensity ofthe applied force. Therefore, the sensing unit 120 may sense bending ofthe display unit 110 based on output values of the strain gauges.

For example, as shown in FIG. 7B, if the display unit 110 is bent in thehorizontal direction, a force is applied to strain gauges 51-p, . . . ,51-p+5, 51-r, . . . , 51-r+5 arranged in a bending area, among aplurality of strain gauges arranged on the front surface of the displayunit 110. Also, the strain gauges 51-p, . . . , 51-p+5, 51-r, . . . ,51-r+5 output resistance values according to an intensity of the appliedforce. Therefore, the sensing unit 120 senses an area 52, including allof points at which strain gauges outputting resistance values differentthan in the circle state are positioned, as one bending area.

If lengths of strain gauges increase according to an applied force, thestrain gauges output increased resistance values. If the lengths of thestrain gauges decrease, the strain gauges output decreased resistancevalues. Therefore, the sensing unit 120 may sense a line, which connectsstrain gauges outputting the largest resistance values, or a line, whichconnects strain gauges outputting the smallest resistance values, as abending line in consideration of a bending direction.

Here, when a surface of the display unit 110 is x-y plane on a2-dimensional surface, the bending direction may be divided intodirection Z+ that is a front direction of the display unit 110 anddirection Z− that is a back direction of the display unit 110, based onaxis Z perpendicular to the x-y plane.

Strain gauges may be arranged on a surface or both surfaces of thedisplay unit 110. If the strain gauges are arranged on both surfaces ofthe display unit 110, i.e., in the front and back directions, the straingauges arranged in the front direction may sense concave bending in thefront direction, i.e., in the direction Z+, and the strain gaugesarranged on the back surface may sense concave bending in the backdirection, i.e., in the direction Z−.

If the strain gauges are arranged on one surface of the display unit110, i.e., on the front or back surface, the strain gauges may berealized as shapes that sense bending of the display unit 110 toward thefront surface and bending of the display unit 110 toward the backsurface. For example, as shown in FIG. 7B, if strain gauges are arrangedon the front surface of the display unit 110, the sensing unit 120 maysense a line, which connects strain gauges outputting the smallestresistance values if the display unit 110 is bent in the direction Z+,as a bending line. Also, although not shown in FIG. 7B, if strain gaugesare arranged on the front surface of the display unit 110, and thedisplay unit 110 is bent in the direction Z−, the sensing unit 120 maysense a line, which connects strain gauges outputting the largestresistance values, as a bending line.

FIGS. 8A through 8D are views illustrating a method of sensing rollingin a flexible display device according to an exemplary embodiment.

FIGS. 8A and 8B illustrate whole rolling for rolling an entire area ofthe display unit 110. If the entire display unit 110 is rolled, thewhole area of the display unit 110 is bent to a preset curvature ormore, and thus forces having approximate intensities are applied to bendsensors and strain gauges within a preset range.

If the entire display unit 110 is rolled, the front and back surfaces ofthe display unit 110 may touch each other. Therefore, the sensing unit120 may determine whether the display unit 110 is rolled, according towhether the front and back surfaces of the display unit 110 touch eachother. In this case, the sensing unit 120 may include touch sensors.

Therefore, if resistance values output from all points of the bendsensors or the strain gauges approximate one another within a presetrange greater than a preset value, and the touch sensors arranged on thefront and back surfaces of the display unit 110 sense touches, theflexible display device 100 may determine that the entire display unit110 is rolled.

FIGS. 8C and 8D illustrate partial rolling for rolling a partial area ofthe display unit 110. If the display unit 110 is partially rolled, bendsensors or strain gauges arranged in the rolling area output approximateresistance values within a preset range, as in the case of rolling anentire display unit. Also, the front and back surfaces of the displayunit 110 touch each other in the rolled area. An unrolled area is a flatstate and thus has the same resistance value as a circle state.

Therefore, if resistance values output from bend sensors or straingauges arranged in an area of the display unit 110 approximate oneanother within a preset range greater than a preset value, and touchsensors arranged on the front and back surfaces of the display unit 100sense touches in the corresponding area, the flexible display device 100may sense that the display unit 110 is partially rolled.

In the above-described exemplary embodiment, if the display unit 110 isrolled, the front and back surfaces of the display unit 110 have beendescribed as touching each other, but this is only an exemplaryembodiment. In other words, although the display unit 110 is rolledaccording to characteristics (e.g., a material, a shape, a size, athickness, etc.) of the display unit 110, the front and back surfaces ofthe display unit 110 may not touch each other.

In this case, the sensing unit 120 may sense whether the front and backsurfaces of the display unit 110 touch each other, by using magneticsensors, magnetic field sensors, photo sensors, proximity sensors, orthe like. Also, the flexible display device 100 may determine whetherthe display unit 110 is rolled, based on the sensing result of thesensing unit 120.

As described above, the flexible display device 100 may be changed intovarious shapes and may sense the changed shapes based on the sensingresult of the sensing unit 120.

The flexible display device 100 may also detect a bending degree, i.e.,a bending angle, based on the sensing result of the sensing unit 120.

Although not shown in the drawings, the flexible display device 100determines a bending degree thereof by using changes in sizes ofresistance values output at preset intervals from bend sensors. Indetail, a bend sensor calculates a difference between a resistance valueof a point outputting the greatest resistance value and a resistancevalue output from a point having a preset distance from the pointoutputting the greatest resistance value.

Also, the flexible display device 100 may determine a bending degree byusing the calculated difference between the resistance values. Indetail, the flexible display device 100 may divide the bending degreeinto a plurality of levels, and match and store resistance values havingpreset ranges on each of the levels.

Therefore, the flexible display device 100 may determine a bendingdegree thereof according to levels belonging to the plurality of levelsinto which the calculated difference between the resistance values aredivided according to the bending degree.

The flexible display device 100 may perform an appropriate operationaccording to the bending degree. For example, the flexible displaydevice 100 may be realized as an electronic device that selects andoutputs a broadcast signal. In this case, if the flexible display device100 performs a channel zapping operation, the flexible display device100 may increase a channel zapping speed and a channel zapping rangeaccording to the bending degree. If the bending degree is low, theflexible display device 100 may perform the channel zapping according tothe smaller number of channels. However, this is only an exemplaryembodiment, and even when controlling a volume, changing contents, orthe like, the flexible display device 100 may perform differentoperations according to the bending degree.

As described above, the bending direction of the display unit 110 may bedivided into the directions Z+ and Z−. In other words, when the surfaceof the display unit 110 is the x-y plane on the 2-dimensional surface,the bending direction may be divided into the direction Z+ that is thefront direction of the display unit 110 and the direction Z− that is theback direction of the display unit 110, and the flexible display device100 may determine the bending direction of the display unit 110 throughvarious methods.

FIGS. 9A through 9D are views illustrating a method of sensing a bendingdirection by using bend sensors that overlap each other, according to anexemplary embodiment. For convenience of description, FIGS. 9A through9D illustrate bending. However, rolling may also be applied in thisembodiment like bending.

Referring to FIG. 9A, the sensing unit 120 may include two bend sensors61 and 62 that overlap each other on a surface of the display unit 110.In this case, if bending is performed in one direction, resistancevalues of the upper bend sensor 61 and the lower bending sensor 62 aredifferently detected at a point at which the bending is performed.Therefore, if the resistance values of the two bend sensors 61 and 62are compared with each other at the same point, a bending direction maybe sensed.

In detail, if the display unit 110 is bent in direction Z+ as shown inFIG. 9B, a greater tensile force is applied to the lower bend sensor 62than to the upper bend sensor 61 at point A corresponding to a bendingline.

On the contrary to this, if the display unit 110 is bent in direction Z−as shown in FIG. 9C, a greater tensile force is applied to the upperbend sensor 61 than to the lower bend sensor 62.

Therefore, the flexible display device 100 may compare resistance valuesof the two bend sensors 61 and 62 corresponding to the point A to sensethe bending direction.

Two bend sensors overlap each other on the surface of the display unit110 in FIGS. 9A through 9C, but the sensing unit 120 may include bendsensors that are arranged on both surfaces of the display unit 110.

FIG. 9D illustrates the two bend sensors 61 and 62 that are arranged onboth surfaces of the display unit 110.

Therefore, when the display unit 110 is bent in the direction Z+, a bendsensor arranged on a first surface of the display unit 110 receives acompressive force, and a bend sensor arranged on a second surfacereceives a tensile force. When the display unit 110 is bent in thedirection Z−, the bend sensor arranged on the second surface receives acompressive force, and the bend sensor arranged on the first surfacereceives a tensile force. As described above, values detected from twobend sensors may be different from each other according to the bendingdirection, and the flexible display device 100 may divide the bendingdirection according to detection characteristics of the values.

The bending direction is sensed by using the two bend sensors asdescribed with reference to FIGS. 9A through 9D but may be divided byusing only strain gauges arranged on the surface of the display unit110. In other words, the strain gauges arranged on the surface receive acompressive force or a tensile force according to their bendingdirection, and thus characteristics of output values of the straingauges may be checked to sense the bending direction.

FIGS. 10A and 10B are views illustrating a method of sensing a bendingdirection according to another exemplary embodiment.

For example, FIGS. 10A and 10B are views illustrating a method ofsensing a bending direction by using acceleration sensors. Referring toFIGS. 10A and 10B, the sensing unit 120 includes a plurality ofacceleration sensors 71-1 and 71-2 that are arranged in an edge area ofthe display unit 110.

The acceleration sensors 71-1 and 71-2 are sensors that may measureaccelerations and directions of the accelerations when motions occur. Indetail, the acceleration sensors 71-1 and 71-2 output sensing valueswhich correspond to gravity acceleration, which varies according to aslope of a device to which the acceleration sensors 71-1 and 71-2 areattached. Therefore, if the acceleration sensors 71-1 and 71-2 arerespectively arranged in edge areas of both sides of the display unit110, output values sensed by the acceleration sensors 71-1 and 71-2 varywhen the display unit 110 is bent. The flexible display device 100calculates a pitch angle and a roll angle by using the output valuessensed by the acceleration sensors 71-1 and 71-2. Therefore, a bendingdirection may be determined based on change degrees of the pitch angleand the roll angle sensed by the acceleration sensors 71-1 and 71-2.

FIG. 10A illustrates the acceleration sensors 71-1 and 71-2 that arearranged at both lateral edges on the front surface of the display unit110. However, acceleration sensors 71-3 and 71-4 may be arranged in alongitudinal direction as shown in FIG. 10B. In this case, if thedisplay unit 110 is bent in a vertical direction, a bending directionmay be sensed according to measurement values sensed by the accelerationsensors 71-3 and 71-4 arranged in the longitudinal direction.

Acceleration sensors are arranged at left and right edges or upper andlower edges of the display unit 110 in FIGS. 10A and 10B but may bearranged at all of the upper, lower, left, and right edges or in cornerareas.

The bending direction may be sensed by using gyro sensors or geomagneticsensors besides acceleration sensors as described above. If a rotarymotion occurs, the gyro sensors measure Coriolis' force acting in aspeed direction of the rotary motion to detect an angular speed. Arotation direction may be detected according to the measurement valuesof the gyro sensors, and thus the bending direction may be sensed. Thegeomagnetic sensors sense azimuth by using biaxial or triaxial fluxgates. If the acceleration sensors are realized as the geomagneticsensors, the geomagnetic sensors arranged at respective edges of theflexible display device 100 perform location movements if the edges arebent, and thus output electric signals corresponding to geomagneticchanges caused by the location movements. The flexible display device100 may calculate a yaw angle by using values output from thegeomagnetic sensors. Therefore, various bending characteristics, such asa bending area, a bending direction, etc., may be determined accordingto changes in the calculated yaw angle.

As described above, the flexible display device 100 may determine adirection in which a shape change is made, by using various types ofsensors. Structures and sensing methods of the above-described sensorsmay be individually applied to the flexible display device 100 or may becombined with one another to be applied to the flexible display device100.

The sensing unit 120 may sense a manipulation of a user who touches ascreen of the display unit 110. In this case, the sensing unit 120 mayinclude decompressive or capacitive touch sensors to sense coordinatesof a point touched by the user.

The control unit 130 controls an overall operation of the flexibledisplay device 100. In particular, the control unit 130 may determine achange in the shape of the flexible display device 100, based on thesensing result of the sensing unit 120. Here, the change in the shapeincludes bending and rolling. In other words, the control unit 130 maydetermine whether the display unit 110 is bent, a bending degree of thedisplay unit 110, a bending direction of the display unit 110, whetherthe display unit 110 is rolled, a rolling degree of the display unit110, a rolling direction of the display unit 110, etc., by using a valuesensed by the sensing unit 120.

In particular, the control unit 130 may perform a first function of theflexible display device 100 that is performable in a rolling modedetermined by a rolling characteristic detected by the sensing unit 120.Here, the rolling mode may be determined according to a rolling shape,for example, the rolling mode may include rolling shapes such as a conicshape, a cylindrical shape, whole and/or partial rolling shapes, etc.Also, in case of conic shape, a rolling shape in which a diameter of anupper area is greater and a rolling shape in which a diameter of a lowerarea is greater may be classified as different rolling modes. Inaddition, a rolling shape that is changed by a rigid body part (e.g., arolling shape changed by the main body 2100 of FIG. 5) may also beincluded in the rolling mode.

Information about functions performable in respective rolling modes maybe pre-stored in the flexible display device 100 or may be received froman external source. In other words, information about a functionperformable in the conic shape, a function performable in thecylindrical shape, a function performable in the whole rolling shape, afunction performable in the partial rolling shape, etc. may bepre-stored. For example, in the cylindrical shape, an audio function, amicrophone function, a pointing function for controlling an externaldevice, etc. may be stored to be performable according to a size of arolling diameter.

Also, the functions performable in the respective rolling modes may bedetermined according to a function that is being performed in theflexible display device 100 right before rolling, a contentcharacteristic displayed on the screen, etc. For example, if theflexible display device 100 is rolled to have a preset rolling diameteror less in an external device control mode, the flexible display device100 may perform a pointing function.

The rolling characteristic may include at least one selected from arolling diameter, and a size, a position, and a shape of an area exposedby rolling as described above. Here, the exposed area may be a rolledarea or an unrolled area in the case of partial rolling.

If the display unit 110 is rolled, a rolling diameter varies accordingto a rolling degree, and thus the control unit 130 may determine therolling degree based on the rolling diameter.

In detail, when the display unit 110 is rolled, the control unit 130 maydetermine the rolling diameter based on resistance values output frombend sensors or strain gauges. In this case, a table matching rollingdiameters according to output resistance values may be pre-stored.

The sensing unit 120 may include magnetic sensors or proximity sensorsarranged in an edge area of the display unit 110 to sense a rollingdegree of the display unit 110. In this case, when the display unit 110is rolled, the control unit 130 may determine two different displaypoints at which virtual rolling diameters meet or may determine aproximity degree between areas based on values sensed by the magneticsensors or the proximity sensors. Also, when the proximity degree isgreat, the control unit 130 may determine that the rolling degree isgreat.

When the display unit 110 is rolled, and the rolling diameter is changedby the user, the control unit 130 may perform a function correspondingto the changed rolling diameter.

Also, when the display unit 110 is rolled, and at least one of therolling diameters corresponding to the plurality of rolling areas ischanged, the control unit 130 may perform a function corresponding tothe changed rolling diameter. For example, if a rolling diameter isgreater than or equal to a preset value, the control unit 130 mayperform a music play function. If the rolling diameter is less than thepreset value, the control unit 130 may perform a microphone function.

In addition, when the display unit 110 is rolled, the control unit 130may perform a mapped function corresponding to a manipulation of movinga rolling axis. For example, the manipulation of moving the rolling axismay be mapped onto a touch input, such as an existing tab or an existingscroll, to be used.

If whole rolling, which relates to rolling an entire area of the displayunit 110, is sensed, the control unit 130 may perform a functioncorresponding thereto. If partial rolling, which relates to rolling apartial area of the display unit 110, is sensed, the control unit 130may perform a function corresponding thereto. For example, if wholerolling is sensed, the control unit 130 may perform a screen mode changefunction. If partial rolling is sensed, the control unit 130 may performa sub function of a content that is already displayed.

Also, if at least a partial area of the display unit 110 is exposedbecause of a manipulation of unrolling the display unit 110, the controlunit 130 may reconstitute an image according to a size of the exposedpartial area and display the reconstituted image in the exposed partialarea. For example, the control unit 130 may adjust a ratio of an imageframe according to a size of an exposed area and display the imageframe.

As a method of determining a display surface that will provide a screensuch as a UI screen or the like in order to perform a functioncorresponding to a rolling characteristic, through the control unit 130,the following method may be used.

Determining Display Surface for Providing Screen According to Rolling

1) Determining a Display Surface Through a Touch Input

The control unit 130 may determine an area, which receives a touch inputof the user, as a display area on a 360-degree direction screen formedby rolling and provide a screen onto a corresponding surface. In thiscase, the control unit 130 may determine an area, which receives anadditional touch input of the user except a part gripped by the user, asa display area.

2) Determining a Display Surface Through a Face Recognition

The control unit 130 may determine a display surface through a facerecognition performed by a camera (not shown). For example, the controlunit 130 may recognize a face by using the camera (not shown) todetermine the display surface. Although a clear face shape is notrecognized, the control unit 130 may recognize at least one facecharacteristic part, such as a face shape, eyebrows, eyes, nose, mouth,hair, or the like, to determine an area watched by the user.

3) Determining a Display Surface by Using an Accelerometer

The control unit 130 may determine a display surface according to asensing result of the sensing unit 120 that is detected by using abending line and the accelerometer. However, in this case, the user maycontrol the display surface of the flexible display device 100 in anopposite direction to a gravity acceleration direction, i.e., by lookingat the flexible display device 100 from top to bottom.

The control unit 130 may determine a position of the flexible displaydevice 100 by using a sensing result of the accelerometer. For example,the control unit 130 may determine a position of a screen on which theaccelerometer is installed, by using a gravity acceleration resultsensed by the accelerometer and determine a position of another screenaccording to a bending shape. The control unit 130 may determine ascreen, which is in the opposite direction to the gravity accelerationdirection, as the display surface.

4) Determining a Display Surface According to a Gripping Motion of theUser

If a two-handed gripping motion is performed, the control unit 130determines a surface, on which two thumbs are placed in a pressuresensor, a touch sensor, or the like in an area touched by the two thumbsand other fingers, as a display surface.

If a one-handed gripping motion is performed, the control unit 130determines a surface, on which the thumb is placed in the pressuresensor, the touch sensor, or the like in an area touched by the thumband the other fingers, as a display surface. In this case, the controlunit 130 may determine a display surface according to the number offingers sensed on one of front and back surfaces on which fingers areplaced or a shape of the surface where the fingers are placed.

5) Determining a Display Surface if a Surface is Within a PresetDistance Range from a Particular Object

If a surface of a 360-degree screen is close to or touches an obstacledue to rolling, the control unit 130 may exclude the correspondingsurface from a display surface.

However, when whole rolling (as described above), the control unit 130may preset a display area in consideration of an area that may begripped by a hand. Therefore, the control unit 130 may provide the userwith a guide to a gripped area.

Although not shown in the drawings, an input unit (not shown) receives aselection of a surface corresponding to a user interface, which isprovided through the display unit 110, from the user. For example, ifthe flexible display device 100 is rolled, the user may select aparticular area through the input unit (not shown). The user may alsodesignate an area, which will display the user interface, through theinput unit (not shown).

Here, if the display unit 110 is realized as a touch screen type thatforms a layer structure with a touch pad, the input unit (not shown) mayform a single body with the display unit 110. In this case, the touchscreen may be constituted to detect a touch input position, a touchinput area, and touch input pressure.

The input unit (not shown) may also receive a user command forcontrolling an electronic device through the user interface providedthrough the display unit 110.

A UI processing unit (not shown) processes and/or generates varioustypes of UIs as 2D or 3D forms. Here, as described above, the UIs may bevarious types of control mode UIs corresponding to changes in the shapeof the flexible display device 100. The UI processing unit may alsoperform jobs such as 2D and/or 3D changes of UI elements, transparency,colors, sizes, shapes, and position adjustments, highlights, animationeffects, etc.

A rolling direction refers to a direction in which the display unit 110is rolled. When the display unit 110 is rolled, the control unit 130 maydetermine a direction in which the display unit 110 is rolled, based onpositions of bend sensors or strain gauges that first output resistancevalues different than in an original state. For example, if straingauges that are arranged in a left edge area on the front surface of thedisplay unit 110 first output resistance values different than in theoriginal state, the control unit 130 may determine that the display unit110 is rolled from the left side. According to this method, the controlunit 130 may determine a direction in which the display unit 110 isrolled, i.e., a, left, right, upper, lower, diagonal direction, or thelike.

The control unit 130 may also determine the rolling direction by usingacceleration sensors (not shown) that are arranged at an edge of thedisplay unit 110. In other words, if the display unit 110 is rolled, theacceleration sensor that is positioned in the rolling direction of thedisplay unit 110 senses a slope. The control unit 130 may determine therolling direction based on values sensed by the acceleration sensorsarranged in left, right, upper, and lower areas of the display unit 110.

If the display unit 110 is rolled, the sensing unit 120 may sense anexposed area of a whole area of the display unit 110 that is exposedwhen the display unit 110 is rolled. Here, the exposed area may refer toan area in which a screen of the display unit 110 is exposed.

According to an exemplary embodiment, a size of the exposed area exposedby rolling may be determined by a rolling degree. For this, informationabout the size of the exposed area determined by the rolling degree maybe stored in the storage unit 140 (as shown in FIG. 11). Here, therolling degree may be determined based on sizes of output values outputfrom bend sensors or strain gauges, and a size of an exposed areacorresponding to sizes of output resistance values may be calculated andstored. For example, if the display unit 110 is wholly rolled in ahorizontal direction, and an output value is determined, informationindicating that a display area corresponding to a length of transversedirection A1 is an exposed area, may be pre-stored. Therefore, if therolling degree is determined based on the sensing result of the sensingunit 120, the control unit 130 may control to read informationcorresponding to the determined rolling degree from the storage unit 140in order to process and display an image appropriate for the size of theexposed area.

According to another exemplary embodiment, the sensing unit 120 mayinclude touch sensors that are arranged at preset intervals on the frontand back surfaces of the display unit 110, to determine the exposed areaexposed by the rolling. Also, if the display unit 110 is rolled, thecontrol unit 130 may determine the size and a position of the exposedarea based on the sensing result of the sensing unit 120.

If the display unit 110 is wholly rolled toward an inner surface, i.e.,the display unit 110 is wholly rolled to make a display surface concave,a whole area of the display surface is covered, and thus an exposed areadoes not exist.

However, if the display unit 110 is wholly rolled toward an outersurface, i.e., the display unit 110 is wholly rolled to make the displaysurface convex, the sensing unit 120 senses touches on the back surfaceof the display unit 110 by using touch sensors arranged on the frontsurface of the display unit 110. Here, the control unit 130 maydetermine an area, in which the touch sensors that are arranged on thefront surface of the display unit 110 and the ones on the back surfaceof the display unit 110 (which are not touched) are arranged, as anexposed area and may determine a size and a position of the exposed areabased on a size and a position of the area in which the untouched touchsensors are arranged. Also, if the display unit 110 is partially rolledtoward the outer surface, the control unit 130 may determine an exposedarea by using the above-described method. In other words, the controlunit 130 may determine the area, in which the touch sensors that arearranged on the front surface of the display unit 110 and do not touchthe back surface are arranged, as an exposed area.

If the display unit 110 is partially rolled toward the inner surface,the control unit 130 may determine the exposed area based on outputvalues output from bend sensors or strain gauges. If the display unit110 is partially rolled toward the inner surface, an exposed displaysurface is not bent. Therefore, the control unit 130 may determine anarea, in which bend sensors or strain gauges outputting the sameresistance values as in a flat state are distributed, as an exposed areaand may determine a size and a position of the exposed area by using asize and a position of the area in which the corresponding sensors arearranged.

If the display unit 110 is rolled, the control unit 130 calculates across-section radius in the rolling state based on the sensing result ofthe sensing unit 120 and determines the exposed area according to thecalculated cross-section radius.

The cross-section radius is a radius of a circle formed by the rollingof the display unit 110 and is affected by the rolling degree. In otherwords, as the rolling degree increases, the cross-section radius becomessmall. If the rolling degree is small, the cross-section radius becomesgreat.

Therefore, the flexible display device 100 may pre-store a cross-sectionradius value corresponding to the rolling degree, and the control unit130 may detect a cross-section radius matching with resistance valuesoutput from bend sensors or strain gauges when the display unit 110 isrolled, to calculate the cross-section radius in the rolling state.

The control unit 130 may also determine the exposed area by using thecalculated cross-section radius. In detail, if the display unit 110 isrolled in the right or left direction, the control unit 130 maycalculate a circumference length of the exposed area by using thecross-section radius and perform an arithmetic operation on thecalculated circumference length and a vertical length of the displayunit 110 to calculate the size of the exposed area. If the display unit110 is rolled in the upper or lower direction, the control unit 130 maycalculate a circumference length of the exposed area by using thecross-section radius and perform an arithmetic operation on thecalculated circumference length and a horizontal length of the displayunit 110 to calculate the size of the exposed area.

Also, the sensing unit 120 may sense a user grip area that is covered bygripping of the user in the exposed area. In detail, the user grip areamay be an area of the display unit which is gripped or covered by a bodypart of the user, e.g., may be an area touched by a palm.

Therefore, when the flexible display device 100 is rolled, the sensingunit 120 may sense the user grip area through sensors that may sense auser touch, such as a pressure sensor, a touch sensor, etc.

In detail, the sensing unit 120 may include a touch sensor that senses atouch area of the display unit 110. Here, if a touch area having apreset size or more is sensed for a preset time in the rolling state,the control unit 130 may determine the touch area as the user grip area.

The sensing unit 120 may include a pressure sensor for sensing pressureapplied to the display unit 110. Here, if pressure having a preset sizeor more is sensed for a preset time in the rolling state, the controlunit 130 may determine an area, from which the pressure is sensed, asthe user grip area.

FIG. 11 is a block diagram illustrating a detailed structure of aflexible display device to describe operations according to variousexemplary embodiments.

Referring to FIG. 11, the flexible display device 100 includes thedisplay unit 110, the sensing unit 120, the control unit 130, thestorage unit 140, a communicator 150, an audio processor 170, a videoprocessor 175, a speaker 185, external input ports 191, 192, 193, and194, and a power supply unit 180.

The display unit 110 has a flexible characteristic. The structure andthe operation of the display unit 110 have been described above indetail, and their repeated descriptions will be omitted.

The storage unit 140 may store various types of programs or data relatedto the operation of the flexible display device 100, set-up informationset by the user, a system operating software, various types ofapplication programs, etc.

The storage unit 140 may also store information about the plurality offunctions described above and information about priorities allocated tothe plurality of functions.

The storage unit 140 may also store information about at least onefunction selected from functions respectively matching with respectiveareas of the display unit 110. Also, the storage unit 140 may storeinformation related to priorities respectively allocated to thefunctions.

The sensing unit 120 senses user manipulations performed in the displayunit 110 and the flexible display device 100, in particular, a bendingmanipulation, a touch manipulation, etc. Referring to FIG. 11, thesensing unit 120 may include various types of sensors such as a touchsensor 124, a geomagnetic sensor 121, an acceleration sensor 123, a bendsensor 125, a pressure sensor 126, a proximity sensor 127, a grip sensor128, etc.

The touch sensor 124 may be realized as a capacitive type or adecompressive type. The capacitive type touch sensor refers to a sensorthat senses micro electricity of the body of the user when a body partof the user touches the surface of the display unit 110, by using adielectric coated on the surface of the display unit 110 to calculatetouch coordinates. The decompressive type touch sensor refers to a touchsensor that includes two electrode plates installed in a remote controldevice to sense a current flowing due to a contact between upper andlower plates of a point touched by the user in order to calculate touchcoordinates. Besides this, an infrared sensing method, a surfaceultrasonic wave propagation method, an integral tension measurementmethod, a piezo effect method, etc. may be used to sense touchmanipulations.

The infrared sensing method refers to a method of sensing a position byusing light that is emitted from an infrared light-emitting diode whentouching a screen of a monitor including an Opto-Matrix-frame with anobject for blocking light such as a finger not to be sensed by anopposite phototransistor.

The surface ultrasonic wave propagation method refers to a methodrealized by a simple principle using a characteristic propagated alongan ultrasonic surface and a characteristic of sound propagated at aregular time and a regular distance, i.e., a method of sensing timeintervals of sound that is reflected and received through a transmitterand a reflector.

Also, the integral tension measurement method uses a structure that, ifa corner is pressed by a hand, and a tension measurement devicepositioned at the pressed corner receives the greatest force amongtension measurement devices installed at four corners, changes thereceived force into an electric signal according to a degree of anincreasing force and transmits the electric signal to a controller. Inthis case, the controller may calculate ratios between electric signalsof the four corners to detect a touch position.

The piezo effect method refers to a method by which a controllercalculates ratios between degrees of pressure of four corners varyingaccording to a degree and a position of touch pressure when a usertouches the four corners to calculate coordinate values.

As described above, the touch sensor 124 may be realized as varioustypes.

The geomagnetic sensor 121 is a sensor for sensing a rotation state anda movement direction of the flexible display device 100. Theacceleration sensor 123 is a sensor for sensing a slope degree of theflexible display device 100. As described above, the geomagnetic sensor121 and the acceleration sensor 123 may be respectively used to detectbending characteristics such as a bending direction, a bending area,etc. of the flexible display device 100. However, besides this, thegeomagnetic sensor 121 and the acceleration sensor 123 may be used todetect the rotation state, a slope state, or the like of the flexibledisplay device 100.

The bend sensor 125 may be realized as various types and various numbersof bend sensors may be used as described above, to sense a bending stateof the flexible display device 100. Various examples of the structureand the operation of the bend sensor 125 have been described above, andthus their repeated descriptions will be omitted.

The pressure sensor 126 senses an amount of pressure applied to theflexible display device 100 when the user performs a touch or bendingmanipulation and provides the sensed amount of pressure to the controlunit 130. The pressure sensor 126 may include a piezo film that isinstalled in the display unit 110 to output an electric signalcorresponding to the amount of pressure. The pressure sensor 126 and thetouch sensor 124 are installed separately from each other in FIG. 11.However, if the touch sensor 124 is realized as a decompressive touchsensor, the decompressive touch sensor may also perform a role of thepressure sensor 126.

The proximity sensor 127 is a sensor for sensing an object that does notdirectly touch the display surface but approaches the display surface.The proximity sensor 127 may be realized as various types of sensorssuch as a high-frequency oscillation-type proximity sensor that forms ahigh frequency magnetic field to sense a current induced by a magneticfield characteristic which varies when an object gets near, a magneticproximity sensor that uses a magnet, a capacitance type proximity sensorthat senses varying capacitance due to an approach of an object, aphotoelectric type proximity sensor, an ultrasonic type proximitysensor, etc.

The grip sensor 127 is a sensor that is arranged at an edge or a handlepart of the flexible display device 100 separately from the pressuresensor 126 to sense a grip of the user. The grip sensor 127 may berealized as a pressure sensor or a touch sensor.

If the control unit 130 analyzes various types of sensing signals sensedby the sensing unit 120 to determine that a bending manipulation hasbeen performed, the control unit 130 may determine active and inactiveareas based on a bending line and display a screen corresponding to theactive area.

For example, the control unit 130 may perform an operation of processingdata acquired through communication with an external device or datastored in the storage unit 140 and outputting the processed data throughthe active area of the display unit 110, the speaker 185, etc. In thiscase, the control unit 130 may communicate with the external device byusing the communicator 150.

The communicator 150 is an element that communicates with various typesof external devices according to various types of communication methods.The communicator 150 may include various types of communication modulessuch as a broadcast receiving module 166, a near field communication(NFC) module 153, a GPS module 165, a wireless communication module 154,etc. Here, the broadcast receiving module 166 may include a terrestrialbroadcast receiving module (not shown) including an antenna, ademodulator, an equalizer, etc. for receiving a terrestrial broadcastsignal, a DMB module for receiving and processing a DMB broadcastsignal, etc. The NFC module 153 is a module for communicating with anexternal device positioned in a short range according to a NFC methodsuch as NFC, Bluetooth, Zigbee, or the like. The GPS module 165 is amodule for receiving a GPS signal from a GPS satellite to detect acurrent position of the flexible display device 100. The wirelesscommunication module 154 is a module that is connected to an externalnetwork to perform communication according to a wireless communicationprotocol such as WiFi, IEEE, or the like. The wireless communicationmodule 154 may further include a mobile communication module that isconnected to a mobile communication network to perform communicationaccording to various types of mobile communication standards such as3^(rd) Generation (3G), 3^(rd) Generation Partnership Project (3GPP),Long Term Evolution (LTE), or the like.

The control unit 130 may control the communicator 150 to receivecontents from the external device or transmit contents to the externaldevice according to a function performed in the active area.

The control unit 130 may also recognize a bending manipulation, a touchmanipulation, a voice input, or a motion input to perform an operationcorresponding to the input. In this case, the control unit 130 mayactivate the voice recognizer 170 or the video processor 175.

The audio processor 170 collects voices of the user or external soundsby using a voice acquiring means such as a microphone 194 and transmitsthe collected voices or sounds to the control unit 130. If the audioprocessor 170 operates in a voice control mode, and a voice of the usercorresponds to a preset voice command, the control unit 130 may performa task corresponding to the voice of the user.

The video processor 175 acquires an image of the user by using an imagepickup means (not shown) such as a camera and provides the acquiredimage of the user to the control unit 130. If the video processor 175operates in a motion control mode, the control unit 130 analyzes theimage of the user to determine that the user makes a motion gesturecorresponding to a preset motion command and performs an operationcorresponding to the motion gesture.

For example, various types of tasks, such as channel zapping, turning-ona device, turning-off a device, pausing, playing, stopping, rewinding,fast-forwarding, muting, etc., may be controlled by voices or motionsbut are limited thereto.

Besides this, first, second, . . . , and n^(th) external input ports maybe respectively connected to various types of external devices toreceive various types of data, programs, control commands, or the like.In detail, a USB port, a headset port, a mouse port, a LAN port, etc.may be included. The power supply unit 180 is an element that suppliespower to respective elements of the flexible display device 100. Thepower supply unit 180 may be realized as a type including an anodecurrent collector, an anode, an electrolyte part, a cathode, a cathodecurrent collector, and a coating enclosing the anode current collector,the anode, the electrolyte part, the cathode, and the cathode currentcollector. The power supply unit 180 is realized as a rechargeable anddischargeable secondary battery. The power supply unit 180 may berealized as a flexible type to be bent together with the flexibledisplay device 100. In this case, a current collector, an electrode,electrolyte, a coating, etc. may be formed of materials having flexiblecharacteristics. Detailed shape and material of the power supply unit180 will be separately described later.

Various types of elements that may be included in the flexible displaydevices 100 are illustrated in FIG. 11. However, the flexible displaydevice 100 may not include all elements and is not limited to aninclusion of only these elements. In other words, some of the elementsmay be omitted or added according to a product type of the flexibledisplay device 100 or may be replaced with other elements.

The control unit 130 controls the elements according to usermanipulations recognized through the sensing unit 120, the audioprocessor 170, the video processor 175, etc., to perform various typesof operations.

FIG. 12 is a block diagram illustrating a detailed structure of thecontrol unit 130 of FIG. 11.

Referring to FIG. 12, the control unit 130 includes a system memory 131,a main CPU 132, an image processor 133, a network interface 134, astorage unit interface 135, first through n^(th) interfaces 136-1through 136-n, an audio processor 137, and a system bus 138.

The system memory 131, the main CPU 132, the image processor 133, thenetwork interface 134, the storage unit interface 135, the first throughn^(th) interfaces 136-1 through 136-n, and the audio processor 137 maybe connected to one another through the system bus 138 to receivevarious types of data, signals, or the like.

The first through n^(th) interfaces 136-1 through 136-n supportinterfaces between various elements including the sensing unit 120 andvarious types of elements of the control unit 130. In FIG. 12, thesensing unit 120 is connected only to the first interface 136-1.However, as shown in FIG. 11, if the sensing unit 120 includes aplurality of various types of sensors, the plurality of various types ofsensors may be respectively connected to interfaces. Also, at least oneinterface selected from the first through n^(th) interfaces 136-1through 136-n may be realized as an input interface that receivesvarious types of signals from a button installed in a body part of theflexible display device 100 or from an external device connected throughfirst through n^(th) external input portsaudio processor.

The system memory 131 includes a ROM 131-1 and a RAM 131-2. A commandset for system booting, etc. are stored in the ROM 131-1. If power issupplied due to an input of a turn-on command, the main CPU 132 copiesan O/S stored in the storage unit 140 into the RAM 131-2 and executesthe O/S to boot a system according to a command stored in the ROM 131-1.If the booting of the system is completed, the main CPU 132 copiesvarious types of application programs stored in the storage unit 140into the RAM 131-2 and executes the application programs copied into theRAM 131-2 to perform various types of operations.

As described above, the main CPU 132 may perform various types ofoperations according to an execution of an application program stored inthe storage unit 140.

The storage unit interface 135 is connected to the storage unit 140 totransmit and receive various types of programs, contents, data, etc.

For example, if at least a partial area of the flexible display device100 is rolled according to a manipulation of the user, the main CPU 132may access the storage unit 140 through the storage unit interface 135to check stored information in order to perform a function correspondingto a rolling characteristic, e.g., a moving picture play function. Inthis state, if the user selects one content, the main CPU 132 executes amoving picture play program stored in the storage unit 140. The main CPU132 controls the image processor 133 to constitute a moving picture playscreen according to a command included in the moving picture playprogram.

The image processor 133 may include a decoder, a renderer, a scaler,etc. Therefore, the image processor 133 decodes a stored content andrenders the decoded content data to constitute a frame, and scales asize of the constituted frame according to a screen size of the displayunit 110. The image processor 133 provides the processed frame to thedisplay unit 110 to display the processed frame.

Additionally, the audio processor 137 refers to an element thatprocesses audio data and provides the processed audio data to a soundoutputting means such as the speaker 185. The audio processor 137 mayperform audio signal processing for decoding audio data stored in thestorage unit 140 or audio data received through the communicator 150,filtering noise from the audio data, amplifying the filtered audio datato an appropriate decibel, etc. In the above-described example, if aplayed content is a moving picture content, the audio processor 137 mayprocess audio data demultiplexed from the moving picture content andsynchronize the processed audio data with the image processor 133 toprovide the synchronized audio data to the speaker 185.

The network interface 134 is a part that is connected to externaldevices through a network. For example, if a web browser program isexecuted, the main CPU 132 accesses a web server through the networkinterface 134. If webpage data is received from the web server, the mainCPU 132 controls the image processor 133 to constitute a webpage screenand displays the constituted webpage screen on the display unit 110.

As described above, if a rolling manipulation is sensed from theflexible display device 100, the control unit 130 may perform anoperation corresponding to the sensed rolling manipulation. Theabove-described operation of the control unit 130 may be realized byexecutions of various types of programs stored in the storage unit 140.

FIG. 13 is a view illustrating a software structure of the storage unit140 for supporting operations of the control unit 130 according to theabove-described various exemplary embodiments. Referring to FIG. 13, thestorage unit 140 includes a base module 141, a device management module,a communication module 143, a presentation module 144, a web browsermodule 145, and a service module.

The base module 141 processes signals transmitted from respective piecesof hardware included in the flexible display device 100 and transmitsthe processed signals to an upper layer module.

The base module 141 includes a storage module 141-1, a location-basedmodule 141-2, a security module 141-3, a network module 141-4, etc.

The storage module 141-1 is a program module that manages a database(DB) or a registry. The location-based module 141-2 is a program modulethat operates together with hardware such as a GPS chip to support alocation-based service. The security module 141-3 is a program modulethat supports certification, permission, secure storage, etc. ofhardware. The network module 141-4 is a module for supporting a networkconnection and includes a DNET module, an UPnP module, etc.

The device management module is a module for managing and usinginformation about an external input and an external device. The devicemanagement module may include a sensing module 142, a device informationmanagement module, a remote control module, etc.

The sensing module 142 is a module that analyzes sensor data providedfrom various types of sensors of the sensing unit 120. In detail, thesensing module 142 is a program module that performs an operation ofdetecting a position of an object or a position, a color, a shape, asize, and other profiles of the user. The sensing module 142 may includea face recognition module, a voice recognition module, a motionrecognition module, an NFC recognition module, etc. The deviceinformation management module is a module that provides informationabout various types of devices. The remote control module is a programmodule that performs an operation of remotely controlling a peripheraldevice such as a phone, a TV, a printer, a camera, an air conditioner,or the like.

The communication module 143 is a module for communicating with anexternal device. The communication module 143 may include a messagingmodule 143-1 including a Short Message Service (SMS) & a MultimediaMessage Service (MMS) program, an e-mail program, etc. and a telephonymodule 143-2 including a call information aggregator program module, aVoIP module, etc.

The presentation module 144 is a module for constituting a displayscreen. The presentation module 144 includes a multimedia module 144-1for playing and outputting multimedia contents and a UI & graphic module144-2 for performing UI and graphic processing. The multimedia module144-1 may include a player module, a camcorder module, a soundprocessing module, etc. Therefore, the multimedia module 144-1 performsan operation of playing various types of multimedia contents to generateand play a screen and a sound. The UI & graphic module 144-2 may includean image compositor module that composes images, a coordinatecombination module that combines and generates coordinates on a screenthat is to display an image, an X11 module that receives various typesof events from hardware, a 2D/3D UI toolkit that provides a tool forconstituting a 2D or 3D UI, etc.

The web browser module 145 refers to a module that performs web browsingto access a web server. The web browser module 145 may include varioustypes of modules such as a web view module that constitutes a webpage, adownload agent module that performs downloading, a bookmark module, awebkit module, etc.

Additionally, the service module refers to an application module forproviding various types of services. For example, the service module mayinclude various types of modules such as a navigation service modulethat provides information about a map, a current position, a landmark, apath, etc., a game module, an advertisement application module, etc.

The main CPU 132 of the control unit 130 accesses the storage unit 140through the storage unit interface 135 to copy various types of modulesstored in the storage unit 140 into the RAM 131-2 and performsoperations according to operations of the copied modules.

In detail, the main CPU 132 analyzes output values of various types ofsensors of the sensing unit 120 to determine whether rolling isperformed, by using the sensing module 142. If it is determined that therolling is performed, the main CPU 132 detects information about afunction corresponding to a rolling characteristic from the DB of thestorage module 141. The main CPU 132 drives a module corresponding tothe detected information to perform an operation.

For example, if a Graphic User Interface (GUI) display operation isperformed, the main CPU 132 constitutes a GUI by using the imagecompositor module of the presentation module 144. The main CPU 132controls the display unit 110 to determine a display position of a GUIscreen and display the GUI screen in the display position by using thecoordinate combination module.

Alternatively, if a user manipulation corresponding to a messagereceiving operation is performed, the main CPU 132 executes themessaging module 143-1 to access a message management server and receivea message stored in a user account. The main CPU 132 also constitutes ascreen corresponding to the received message and displays the screen onthe display unit 110 by using the presentation module 144.

Besides this, if a phone call operation is performed, the main CPU 132may drive the telephony module 143-2.

As described above, various types of programs may be stored in thestorage unit 140, and the control unit 130 may perform operationsaccording to the above-described various exemplary embodiments by usingthe various types of programs stored in the storage unit 140.

FIGS. 14A and 14B are views illustrating rolling characteristicsaccording to an exemplary embodiment.

FIG. 14A is a view illustrating rolling states according to differentrolling diameters.

As shown on left and right sides of FIG. 14A, rolling diameters of thedisplay device 100 may have different values according to the rolledshapes of the display device 100.

A picture shown on the left side of FIG. 14A illustrates a rollingdiameter that is smaller than a preset threshold value, and a pictureshown on the right side illustrates a rolling diameter that is greaterthan the preset threshold value. The flexible display device 100 mayperform different functions according to the rolling diameter.

Also, as shown in FIG. 14A, if the rolling diameter is changed when theflexible display device 100 is rolled, the flexible display device 100may perform a function matching with the changed rolling diameter. Here,the rolling diameter matching with different functions may be dividedinto a plurality of steps. For example, if the rolling diameter issmaller than a first threshold value, the flexible display device 100may perform a first function. If the rolling diameter is between thefirst threshold value and a second threshold value, the flexible displaydevice 100 performs a second function. If the rolling diameter isgreater than the second threshold value, the flexible display device 100may perform a third function. Alternatively, a degree of a levelperformed in the same function may vary according to the rollingdiameter. For example, a volume adjustment may be performed according tothe rolling diameter.

As shown on left and right sides of FIG. 14B, a rolling diameter of thedisplay device 100 may be changed according to a rolled shape of thedisplay device 100.

A picture shown on the left side of FIG. 14B indicates that the flexibledisplay device 100 is rolled such that the rolling diameter is increasedalong a cross-sectional axis running from a lower area of the flexibledisplay device 100 toward an upper area of the flexible display device100. A picture shown on the right side indicates that the flexibledisplay device 100 is rolled such that the rolling diameter decreases'along a cross-sectional axis running from the lower area of the flexibledisplay device 100 toward the upper area. As described above, theflexible display device 100 may perform different functions according toshapes in which the rolling diameter is changed. Alternatively,different functions may be performed according to a position of arolling axis or a degree of a level performed in the same function mayvary according to the position of the rolling axis.

FIGS. 15A through 15C are views illustrating rolling characteristicsaccording to different exemplary embodiments of the present generalinventive concept.

As shown in FIG. 15A, rolling of an entire area of the flexible displaydevice 100 may be defined as a whole rolling state.

Also, as shown in FIGS. 15B and 15C, rolling of a partial area of theflexible display device 100 may be defined as a partial rolling state.

The partial rolling state may include corner rolling as shown in FIG.15B and side rolling as shown in FIG. 15C. The corner rolling mayinclude rolling of a right upper corner area, rolling of a left uppercorner area, and rolling of the left lower corner area and a right lowercorner area, and the side rolling may include rolling of upper, lower,left, and right areas.

FIGS. 16A through 16C are views illustrating a method of controlling aflexible display device according to an exemplary embodiment.

As shown in FIG. 16A, when the flexible display device 100 is rolled, amanipulation of unrolling a rolled end part may be performed.

In this case, as shown in FIG. 16B, a motion of an unrolling operationmay be applied to display a change in a newly displayed content or GUI.For example, as shown in FIG. 16B, rolling directions and displaydirections 141-1 through 141-3 of a text may be displayed to correspondto each other.

Also, as shown in FIG. 16C, rolling directions may correspond todirections 142-1 through 142-3 of a GUI animation to provide a naturalfeedback effect. For example, as shown in FIG. 16C, if the GUI animationis an animation inducing an operation of unrolling a rolled part, theanimation may be connected to an operation of naturally unrolling therolled part in an animation direction to provide user experience (UX).

FIGS. 17A and 17B are views illustrating a method of controlling aflexible display device according to another exemplary embodiment.

As shown in FIGS. 17A and 17B, when the flexible display device 100 isrolled, the rolling of the flexible display device 100 may affect a userinteraction according to whether the user watches a screen in whichdirection. For example, if a GUI element is moved by feedback accordingto whether a rolled area seen by the user is closer to one of the endsof a screen, a movement direction may be determined.

For example, if a manipulation related to maintaining interactionbetween a user and a GUI is performed, the corresponding GUI may providean animation that moves toward the rolled area. If a manipulation ofdeleting a GUI with which a user was interacting, is performed, thecorresponding GUI may show an animation that moves toward the unrolledend.

In this case, if the rolled area is unrolled, an area seen to the usermay be changed according to a rolled direction and a GUI movementdirection may be changed.

As shown in FIG. 17A, if a user manipulation related to keeping a GUI142 displayed in a first area 141 is performed when the user interactswith the first area 141, and a user manipulation of moving the GUI 142in direction A and deleting the GUI 142, the GUI 142 may be moved indirection B. For example, if a user manipulation related to deleting anapplication icon displayed in the first area is performed, thecorresponding application icon may be moved in the direction B so thatthe icon disappears. Also, if a user manipulation related to selectingan application icon displayed in the first area is performed, thecorresponding application icon may be moved in the direction A so thatthe icon disappears, and an application execution screen may bedisplayed according to a selection.

As shown in FIG. 17B, if a user manipulation of deleting a GUI 144displayed in a second area 142′ is performed when the user interactswith the second area 142′, the GUI 144 may be moved in direction C. If auser manipulation related to keeping the GUI 144 is performed, the GUI144 may be moved in direction D.

FIGS. 18A through 20B are views illustrating a method of controlling aflexible display device according to another exemplary embodiment.

As shown in FIGS. 18A through 20B, if the flexible display device 100 isrolled to have a rolling diameter greater than or equal to a presetthreshold value, the flexible display device 100 may perform a firstfunction. If the rolling diameter is reduced when performing the firstfunction, the flexible display device 100 may perform a sub functionprovided within the first function or may perform a second functiondifferent from the first function.

As shown in FIG. 18A, if a rolling manipulation is performed to have arolling diameter greater than or equal to a preset threshold value whenan application execution screen is displayed on a screen of the flexibledisplay device 100, the flexible display device 100 may perform an audiofunction, e.g., a music player function.

Also, when an audio function is performed, a lower function, such asrewinding, fast-forwarding, stopping, pausing, playing, recording, audiotrack changing, or the like, may be performed according to at least oneselected from a changed direction and a changed degree of a rollingaxis.

For example, if a rolling diameter of the flexible display device 100 isreduced according to a user manipulation, a volume size of a soundoutput through the music player function may be reduced.

As shown in FIG. 18B, if the audio function, e.g., the music playerfunction, is performed, and the rolling diameter is reduced according toa user manipulation when the flexible display device 100 is rolled, theflexible display device 100 may perform a microphone function.

When the microphone function is performed, another function, such asoutput audio amplifying, recording, or the like, may be performed basedon the changed direction and/or the changed degree of the rolling axis.

As shown in FIGS. 19A and 19B, a screen mode may be changed into adifferent state according to a rolling degree of the flexible displaydevice 100.

For example, as shown in FIG. 19A, if the flexible display device 100 isrolled to have a rolling diameter smaller than a preset first thresholdvalue, the flexible display device 100 may be changed into a standbystate. Here, the standby state may be a screen off state, a screenlocking state, a security screen state, or the like. The screen offstate refers to a state in which a screen is turned off, and thus aninput using information displayed on the screen is impossible. Thescreen locking state refers to a state in which the screen is turned on,but use of another function is impossible as long as there is nodesignated input. The security screen state refers to a state in whichthe user must perform a designated input in order to activate thescreen.

As shown in FIG. 19B, if the flexible display device 100 is rolled tohave a rolling diameter smaller than a second threshold value smallerthan the first threshold value, the flexible display device 100 may bechanged into a turn-off state. Here, the turn-off state may refer to astate in which power is turned off, and thus all inputs and outputsstop.

As shown in FIGS. 19C and 19D, the flexible display device 100 mayperform different functions according to a rolling degree of theflexible display device 100 and provide UI screens corresponding to thedifferent functions.

As shown in FIG. 19C, if the flexible display device 100 is rolled tohave a rolling diameter smaller than a preset first threshold value, theflexible display device 100 may provide a call function and a phone UIcorresponding to the call function. As shown in FIG. 19D, if theflexible display device 100 is rolled to have a rolling diameter smallerthan a second threshold value which is smaller than the first thresholdvalue, the flexible display device 100 may provide a remote controlfunction and a remote control UI corresponding to the remote controlfunction.

FIGS. 20A and 20B are views illustrating a method of controlling aflexible display device according to another exemplary embodiment.

As shown in FIG. 20A, if rolling a partial area of the flexible displaydevice 100 is performed (i.e., partial rolling), a sub function of anexisting function being performed on a current screen may be performed.

For example, if partial rolling for rolling a partial side area isperformed when a music player function is performed in the flexibledisplay device 100, a playback stop function of stopping music playbackmay be performed.

As shown in FIG. 20B, if partial rolling for rolling a partial area ofthe flexible display device 100 is performed, an additional function ofa function performed on a current screen may be performed.

For example, if partial rolling for rolling a partial corner area isperformed when a content is displayed in the flexible display device100, a locking function of an automatic screen rotation function may beperformed. In detail, although the flexible display device 100 rotatesin a vertical direction when a screen is positioned in a horizontaldirection, contents may not automatically rotate on the screen but maybe kept positioned in the horizontal direction on the screen.

FIGS. 21A and 21B are views illustrating a method of controlling aflexible display device according to another exemplary embodiment.

As shown in FIG. 21A, if rolling an entire area of the flexible displaydevice 100 is performed (e.g., whole rolling), a screen mode changefunction may be performed.

For example, if the whole rolling is performed when the flexible displaydevice 100 displays a screen in a thumbnail mode for displaying aplurality of contents in thumbnail forms, the screen may be changed intoa slide mode.

As shown in FIG. 21B, if a partial area of the flexible display device100 is performed (e.g., partial rolling), a content change function maybe performed while keeping a current screen mode.

For example, if the partial rolling for rolling the partial area isperformed when the flexible display device 100 displays a screen in athumbnail mode for displaying a plurality of contents belonging to afirst folder in thumbnail forms, a plurality of contents belonging to asecond folder may be displayed in thumbnail forms on the screen.

FIGS. 22A through 22D are views illustrating a screen that is displayedwhen unrolling is performed, according to an exemplary embodiment.

As shown in FIGS. 22A and 22B, an image 210 may be displayed on thedisplay unit 110 that is exposed when being rolled. Here, FIG. 22B is aview illustrating the flexible display device 100 of FIG. 22A thatrotates through 180° in a left direction.

If the flexible display device 100 is unrolled, a screen may bedisplayed on the display unit 110 that is newly exposed according to theunrolling. In this case, when the flexible display device 100 is rolled,the flexible display device 100 may enlarge a size of the screendisplayed on the display unit 110 by a size of an area having a flatstate according to the unrolling. Therefore, as shown in FIGS. 22C and22D, an image 210 may be displayed in an area 110-1 that is not exposedwhen being rolled, but is exposed when being unrolled.

If the display unit 110 is locally rolled toward an inner surface, ascreen may be constituted and displayed to correspond to a size and ashape of another area except a bent area due to the rolling.

In detail, if the display unit 110 is partially rolled toward the innersurface, a display surface that is exposed when the partial rolling isperformed may be determined, and a screen may be constituted tocorrespond to a size and a shape of the exposed display surface. If thedisplay unit 110 is partially rolled toward the inner surface, theexposed display surface is not bent. Therefore, the control unit 130 maydetermine a size and a shape of the exposed display surface based on anarea in which bend sensors or strain gauges outputting the sameresistance values as in a flat state are distributed.

If the display unit 110 is locally rolled toward an outer surface, ascreen may be constituted and displayed to correspond to a size and ashape of another area except a part of the inner surface of the displayunit 110 touching the outer surface.

In detail, if the display unit 110 is partially rolled toward the outersurface, a display surface that is exposed by the partial rolling may bedetermined, and a screen may be constituted to correspond to a size anda shape of the exposed display surface. If the display unit 110 ispartially rolled toward the outer surface, a part of the display surfacetouches a back surface of the display unit 110. Therefore, the size andthe shape of the exposed display surface may be determined based on anarea in which touch sensors that are arranged on the front surface anddo not touch the back surface are arranged.

FIGS. 23A and 23B are views illustrating a method of displaying a screenif a display unit is partially rolled, according to an exemplaryembodiment.

As shown in FIG. 23A, if the display unit 110 is partially rolled towardan inner surface, the flexible display device 100 may display an image211 according to a size of an exposed display surface 210. As shown inFIG. 23B, if the display unit 110 is partially rolled toward an outersurface, the flexible display device 100 may display an image 221according to a size of an exposed display surface 220.

As described above, the flexible display device 100 may display a screenaccording to a size of another part of a display surface except a partof the display surface covered by the partial rolling.

If the display unit 110 displays the screen when being rolled, a displayposition of the screen may be adjusted according to a preset standard.Here, the preset standard may be a position of the display surfacewatched by the user when the display unit 110 is rolled. In this case,an area being looked at by the user may be detected within the displayunit 110 through a camera (not shown) for capturing the user. Here, thecontrol unit 130 may trace a face direction of the user, motions ofeyeballs of the user, or the like to detect the area looked at by theuser.

FIGS. 24A through 24E are views illustrating a screen that is displayedwhen a double-sided display unit is unrolled, according to an exemplaryembodiment.

As shown in FIGS. 24A and 24B, an image 221 may be displayed in a firstdisplay area that is exposed by rolling of the display unit 110. Here,FIG. 24B is a view illustrating the flexible display device 100 of FIG.24A that rotates through 180° in a left direction.

If the display unit 110 is unrolled, an image 221 displayed in a firstdisplay area 110-2 disappears from the first display area 110-2 and isdisplayed in a second display area 110-3.

Here, as shown in FIG. 24C, the image 221 displayed in the first displayarea 110-2 is reduced according to a size of a second display area 110-4that is newly exposed by the unrolling. An image 222 that is reduced maybe displayed in the second display area 110-4 that is newly exposed.

As shown in FIGS. 24D and 24E, a part 223 of an image may be displayedin the second display area 110-4 that is newly exposed by the unrolling.If the unrolling is completed, a whole image 224 may be displayed in asecond display area 110-3.

FIG. 25 is a view illustrating a method of controlling a flexibledisplay device according to another exemplary embodiment.

FIG. 25 illustrates the display unit 110 that is wholly rolled toward anouter surface and then put into a support bracket (e.g., a cup) 232. Inthis case, the flexible display device 100 may display an image 231according to a size of another area of a display surface except an areacovered by the support bracket 232.

FIG. 26 is a view illustrating a method of controlling a flexibledisplay device according to another exemplary embodiment.

As shown in FIG. 26, if a user manipulation of gripping and rotatingboth ends of the flexible display device 100 is performed when theflexible display device 100 is rolled, displayed information may berotated and displayed according to a rotation direction of the flexibledisplay device 100.

In this case, if information displayed in an exposed area is limitedwhen the flexible display device 100 is rolled, new information that hasnot been displayed may be displayed according to the rotation of theflexible display device 100. A displayed speed or a displayed amount ofthe new information may vary in proportion to a rotation speed.

FIGS. 27A and 27B are views illustrating a method of controlling aflexible display device according to another exemplary embodiment of thepresent general inventive concept.

As shown in FIG. 27A, object A may have a cylindrical shape.

FIG. 27B illustrates an image that is formed in a flat shape by3-dimensionally scanning the object A. In other words, object B may be3-dimensionally scanned, i.e., may be scanned in a 360° direction, toform a 3D image.

FIG. 27C illustrates display states when the flexible display device 100is not bent and is bent into a cylindrical shape.

As shown with a left picture of FIG. 27C, if the flexible display device100 is not bent, a 2D image of the object A may be displayed. As shownwith a right picture of FIG. 27C, if the flexible display device 100 isbent into the cylindrical shape, an image of the object A may be3-dimensionally displayed over the entire 360° of the display device.

In the above-described exemplary embodiment, a 3D image of an object isformed through 3-dimensional scanning but is not limited thereto.Therefore, the 3D image of the object may be formed as various shapes.

For example, the 3D image of the object may be formed according to acylindrical projection principle. Here, the cylindrical projectionprinciple refers to a principle of enclosing a particular object with acylinder and unfolding the cylinder, i.e., a method of drawing allsurfaces of a 3D object on a 2-D plane. In other words, the cylindricalprojection principle refers to a perspective drawing method of coveringthe 3D object with the cylinder and then emitting light from a center ofa 3D object to draw a surface of the 3D object projected onto thecylinder. A 3D image that uses the cylindrical projection principle maybe formed through a 3D scanner as described above. The 3D scanner may3-dimensionally scan an object, from which a 3D image is to be acquired,at several angles by using a laser or the like and process a pluralityof formed scan images to transform the plurality of formed scan imagesinto a cylindrical shape in order to form 3D graphic data.Alternatively, images that are acquired by capturing an object in two ormore different directions may be attached to form a panorama image. Indetail, the object may be captured in at least two directions to acquirea frame in order to acquire an image that is seen all around in a 360°direction. A background image may be removed from at least two acquiredframes, and only an object image may be extracted and attached toacquire a panorama image of the corresponding object that is seen in the360° direction.

For example, a 3D object may be captured in front and back directions toacquire two images, curved areas of the two acquired images may beunfolded on a plane to process the two acquired images, and theimage-processed images may be attached to form one consecutive image. Inthis case, a fisheye lens that is a super-wide-angle lens having a viewangle exceeding 180° may be used to acquire the captured images.

FIGS. 28A through 28C are views illustrating a method of controlling aflexible display device according to another exemplary embodiment.

As shown in FIGS. 28A through 28C, various types of graphic effects maybe provided according to a manipulation of rolling the flexible displaydevice 100.

As shown in FIG. 28A, if an unrolling manipulation is performed when theflexible display device 100 is rolled, there may be provided a graphiceffect that changes a size of a content displayed in an exposed areaaccording to a size of the area exposed by the unrolling. For example,as shown in FIG. 28A, the size of the content displayed in the exposedarea may increase with an increase in the size of the area exposed bythe unrolling.

As shown in FIG. 28B, if a unrolling manipulation is performed when theflexible display device 100 is rolled, there may be provided a graphiceffect that changes an amount of information displayed in an exposedarea according to a size of the area exposed by the unrolling. Forexample, as shown in FIG. 28B, the amount of the information displayedin the exposed area may increase with an increase in the size of thearea exposed by the unrolling. Here, the amount of information may bethe number of contents, details of contents, additional information, orthe like.

As shown in FIG. 28C, if a unrolling manipulation is performed when theflexible display device 100 is rolled, there may be provided a graphiceffect that changes a position of a content displayed in an exposed areaaccording to a size of the area exposed by the unrolling. For example,as shown in FIG. 28C, a content displayed in a first exposed area mayslide into a newly exposed area to be displayed according to a change inthe area exposed by the unrolling.

FIG. 29 is a view illustrating a method of controlling a flexibledisplay device according to another exemplary embodiment.

As shown in FIG. 29, the flexible display device 100 may be rolled intoa shape for being installed on a charger 270 to be charged. When theflexible display device 100 may be rolled to be charged, the flexibledisplay device 100 may display a charging state on a screen.

FIG. 30 illustrates the flexible display device 100 that is realized asa 3D display device not as a flat-panel display device. Referring toFIG. 30, the display unit 110 is provided on a surface of the flexibledisplay device 100, and various types of pieces of hardware, such asbuttons, a speaker, a microphone, an IR lamp, etc., are provided onanother surface.

An entire part or a part of an outer case of the flexible display device100 as shown in FIG. 30 may be formed of rubber or other types ofpolymer resins to be flexibly bent. Therefore, a whole part or a part ofthe flexible display device 100 may have a flexible characteristic.

The flexible display device 100 may perform a new operation differentfrom a previous operation according to a bending input. For example, theflexible display device 100 may perform a remote control function ofcontrolling an external device in ordinary times but may perform a callfunction if a bending gesture is made in an area. When the remotecontrol function is performed, a remote control button may be displayedon the display unit 110. If the call function is performed, a dial padmay be displayed on the display unit 110.

FIG. 31 illustrates the flexible display device 100 that is realized ina circle shape. Therefore, the flexible display device 100 may performvisually and functionally different operations according to a placedshape or a folded shape. For example, when the flexible display device100 is horizontally placed on a floor, the flexible display device 100may display other contents. If the flexible display device 100 standsvertically on the floor, the flexible display device 100 may perform atable clock function. Alternatively, if a central part of the flexibledisplay device 100 is bent about 90°, the flexible display device 100may perform a notebook PC function. In this case, the flexible displaydevice 100 may display a soft keyboard in one of folded areas anddisplay a display window in the other area.

The flexible display device 100 may be realized as various types.

FIG. 32 is a flowchart illustrating a method of controlling a flexibledisplay device according to an exemplary embodiment.

Referring to FIG. 32, if a display unit is rolled in operation S3210, atleast one rolling characteristic is detected in operation S3220. Here,the rolling characteristic may include at least one selected from arolling diameter of the display unit, and a size, a position, and ashape of an exposed area.

In operation S3230, the flexible display device performs a firstfunction of the flexible display device that is performable in a rollingmode determined according to the detected rolling characteristic. Here,the rolling mode may include a conic shape, a cylindrical shape, apartially rolling shape, a wholly rolling shape, etc. For example, if anentire area of the flexible display device is rolled, and a rollingdiameter of the flexible display device is uniform, the rolling mode maybe determined in the cylindrical shape. In this case, the flexibledisplay device may perform a function that is performable in the rollingmode of the cylindrical shape.

In this case, a display unit may be rolled based on one axis.

Also, if the rolling diameter is changed by a user when the display unitis rolled, the flexible display device may perform a second functioncorresponding to the changed rolling diameter.

Also, if the display unit includes a plurality of rolling areas, theflexible display device may detect rolling diameters respectivelycorresponding to the plurality of rolling areas. If at least oneselected from the rolling diameters respectively corresponding to theplurality of rolling areas is changed when the display unit is rolled,the flexible display device may perform a third function correspondingto the changed rolling diameter.

If whole rolling for rolling an entire area of the display unit issensed, the flexible display device may perform a fourth function. Ifpartial rolling for rolling a partial area of the display unit issensed, the flexible display device may perform a fifth function. Here,the fourth function may be a screen mode change function, and the fifthfunction may be a sub-function of a content displayed on the displayunit.

Also, if at least a partial area of the display unit is exposedaccording to a manipulation of unrolling the display unit, the flexibledisplay device may reconstitute an image according to a size of theexposed partial area and may display the image in the exposed partialarea.

The method of controlling the flexible display device, etc. according tothe above-described various exemplary embodiments may be realized asprograms to be provided to the flexible display device.

In detail, there may be provided a non-transitory computer readablemedium that stores a program performing an operation of detecting arolling characteristic if a display unit is rolled and an operation ofperforming a first function of the flexible display device that isperformable in a rolling mode determined by the detected rollingcharacteristic.

The non-transitory computer-readable medium refers to a medium whichdoes not store data for a short time such as a register, a cache memory,a memory, or the like but semi-permanently stores data and is readableby a device. In detail, the above-described applications or programs maybe stored and provided on a non-transitory computer readable medium suchas a compact disk (CD), a digital versatile disk (DVD), a hard disk, ablue-ray disk, a universal serial bus (USB), a memory card, a read-onlymemory (ROM), or the like.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting. The present teaching can bereadily applied to other types of apparatuses. Also, the description ofthe exemplary embodiments is intended to be illustrative, and not tolimit the scope of the claims, and many alternatives, modifications, andvariations will be apparent to those skilled in the art.

The invention claimed is:
 1. A flexible display device comprising: adisplay; at least one sensor; and at least one controller configured to:based on a folding of the display being detected by the at least onesensor, identify a plurality of areas of the display divided accordingto the folding of the display, and control the display to display afirst screen corresponding to a first function in a first area among theplurality of areas and display a second screen corresponding to a secondfunction different from the first function in a second area among theplurality of areas, wherein the at least one controller is furtherconfigured to: based on the display not being folded, identify a stateof the display based on information detected by the at least one sensor,and based on the identified state of the display being a first state,control the display to display a third screen, and based on theidentified state of the display being a second state, control thedisplay to display a fourth screen different from the third screen, andwherein the first state indicates that the display is placed in a firstposition, and the second state indicates that the display is placed in asecond position different from the first position.
 2. The flexibledisplay device of claim 1, wherein the at least one controller isfurther configured to: receive a user command while the display isfolded, based on the user command being received in the first area,control the display to display a screen corresponding to a functionexecuted by the user command in the first area, and based on the usercommand being received in second area, control the display to displaythe screen corresponding to the function executed by the user command inthe second area.
 3. The flexible display device of claim 1, wherein thefirst screen is controlled by a first application corresponding to thefirst function and the second screen is controlled by a secondapplication corresponding to the second function.
 4. The flexibledisplay device of claim 1, wherein the first screen comprises a softkeyboard and the second screen comprises a content corresponding to afunction executed according to a user command input on the softkeyboard.
 5. The flexible display device of claim 1, wherein the atleast one controller is further configured to: identify a folding angleof the display, and control the display to display different screens onthe plurality of areas based on the identified folding angle beingcorresponded to a predetermined angle.
 6. The flexible display device ofclaim 1, wherein the at least one controller is further configured to:based on the state of the display being identified as a horizontalstate, control the display to display the third screen corresponding toa third function, and based on the state of the display being identifiedas a vertical state, control the display to display the fourth screencorresponding to a fourth function different from the third function. 7.The flexible display device of claim 6, wherein one of the thirdfunction and the fourth function is a clock function.
 8. The flexibledisplay device of claim 1, wherein the third screen corresponds to oneof the first function and the second function.
 9. A method ofcontrolling a flexible display device, the method comprising: based on afolding of a display of the flexible display device being detected,identifying a plurality of areas of the display divided according to thefolding of the display; and displaying a first screen corresponding to afirst function in a first area among the plurality of areas anddisplaying a second screen corresponding to a second function differentfrom the first function in a second area among the plurality of areas,wherein the method further comprises: based on the display not beingfolded, identifying a state of the display based on information detectedby at least one sensor of the flexible display device, and based on theidentified state of the display being a first state, displaying a thirdscreen, and based on the identified state of the display being a secondstate, displaying a fourth screen different from the third screen, andwherein the first state indicates that the display is placed in a firstposition, and the second state indicates that the display is placed in asecond position different from the first position.
 10. The method ofclaim 9, further comprising: receiving a user command while the displayis folded; based on the user command being received in the first area,displaying a screen corresponding to a function executed by the usercommand in the first area; and based on the user command being receivedin second area, displaying the screen corresponding to the functionexecuted by the user command in the second area.
 11. The method of claim9, wherein the first screen is controlled by a first applicationcorresponding to the first function and the second screen is controlledby a second application corresponding to the second function.
 12. Themethod of claim 9, wherein the first screen comprises a soft keyboardand the second screen comprises a content corresponding to a functionexecuted according to a user command input on the soft keyboard.
 13. Themethod of claim 9, further comprising: identifying a folding angle ofthe display, and displaying different screens on the plurality of areasbased on the identified folding angle being corresponded to apredetermined angle.
 14. The method of claim 9, further comprising:based on the state of the display being identified as a horizontalstate, displaying the third screen corresponding to a third function,and based on the state of the display being identified as a verticalstate, displaying the fourth screen corresponding to a fourth functiondifferent from the third function.
 15. The method of claim 14, whereinone of the third function and the fourth function is a clock function.16. The method of claim 9, wherein the third screen corresponds to oneof the first function and the second function.